1. Technical Field
The present invention is related to a shovel including a boom regenerative hydraulic motor and a method for controlling the shovel.
2. Description of Related Art
Until now, a hybrid type shovel including an electric motor generator for a boom, an electric motor generator for an engine, and an electric motor generator for a swing body is known. The boom-driving electric motor generator is rotationally driven by a boom regenerative hydraulic motor when lowering a boom. The electric motor generator for an engine is rotationally driven by an engine. The electric motor generator for a swing body is capable of a regenerating operation and a power running operation.
This hybrid type shovel shifts the electric motor generator for an engine to its power running operation when the electric motor generator for a boom or the electric motor generator for a swing body is in its regenerative operation. Thus, the hybrid type shovel can use regenerated electric power for driving the electric motor generator for an engine without charging a battery, and thus can make more efficient use of the regenerated electric power.